JP2852161B2 - Amplifier using amplified optical fiber - Google Patents
Amplifier using amplified optical fiberInfo
- Publication number
- JP2852161B2 JP2852161B2 JP4174415A JP17441592A JP2852161B2 JP 2852161 B2 JP2852161 B2 JP 2852161B2 JP 4174415 A JP4174415 A JP 4174415A JP 17441592 A JP17441592 A JP 17441592A JP 2852161 B2 JP2852161 B2 JP 2852161B2
- Authority
- JP
- Japan
- Prior art keywords
- amplifier
- optical
- optical fiber
- isolator
- fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/06754—Fibre amplifiers
- H01S3/06758—Tandem amplifiers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S2301/00—Functional characteristics
- H01S2301/02—ASE (amplified spontaneous emission), noise; Reduction thereof
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Optics & Photonics (AREA)
- Lasers (AREA)
- Optical Communication System (AREA)
- Glass Compositions (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Organic Insulating Materials (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
- Preliminary Treatment Of Fibers (AREA)
- Insulators (AREA)
- Light Guides In General And Applications Therefor (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えばエルビウムのド
ーピングによって増幅作用を与えた光ファイバを用いる
増幅器に関する。この種の増幅器は主に海底光ファイバ
通信システムで使用される。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an amplifier using an optical fiber which has been amplified by, for example, erbium doping. This type of amplifier is mainly used in submarine optical fiber communication systems.
【０００２】[0002]
【従来の技術及び発明が解決しようとする課題】エルビ
ウムをドープした光ファイバを用いた増幅器は例えば仏
国特許第２ ６３８ ８５４号で知られており、対応す
る海底伝送システムも公知である。この種の増幅器を使
用すると、１．５〜１．６マイクロメートルのスペクト
ル範囲で、光ファイバに信号を通すだけで大きな利得が
得られる。しかしながら公知のように（Ｊ．Ｆ．ＭＡＲ
ＣＥＲＯＵら、Ｐｒｏｃｅｅｄｉｎｇｓ ＳＰＩＥ １
３７３，ｐｐ．１６８−１８６，１９９１参照）、エル
ビウムをドープした光ファイバを用いた増幅器は、これ
を十二分に活用したいと思っても、ＡＳＥ（ａｍｐｌｉ
ｆｉｅｄ ｓｐｏｎｔａｎｅｏｕｓ ｅｍｉｓｓｉｏ
ｎ）と称する光ノイズを発生するため限界がある。ＡＳ
Ｅはレーザ媒質の飽和の一因をなすが、これは光ファイ
バ上に存在する１つ又は複数の信号の増幅を犠牲にして
発生する。ところが、ＡＳＥが優れた広帯域スーパーフ
ルオレセント（ｓｕｐｅｒ−ｆｌｕｏｒｅｓｃｅｎｔ）
光源の形成に使用されるのは、このような理由によるも
のなのである。BACKGROUND OF THE INVENTION Amplifiers using erbium-doped optical fibers are known, for example, from French Patent No. 2,638,854, and corresponding undersea transmission systems are also known. With this type of amplifier, a large gain can be obtained simply by passing a signal through an optical fiber in the spectral range of 1.5 to 1.6 micrometers. However, as is known (JF MAR)
CEROU et al., Proceedings SPIE 1
373, pp. 168-186, 1991), an amplifier using an erbium-doped optical fiber can be fully utilized by an ASE (ampli).
feed spontaneous emissio
There is a limit for generating optical noise referred to as n). AS
E contributes to saturation of the laser medium, which occurs at the expense of amplification of one or more signals present on the optical fiber. However, ASE is excellent in broadband super-fluorescent.
It is for this reason that it is used to form the light source.
【０００３】この問題の解決方法は既に幾つか提案され
てきた。雑音指数を低下させるには短い光ファイバを使
用し得るが、そうすると利得に問題が生じる。また、非
最適化ファイバを使用することもできるが、その場合は
必要なポンピング力が大きくなりすぎる。Several solutions to this problem have already been proposed. Short optical fibers can be used to reduce the noise figure, but this causes gain problems. It is also possible to use non-optimized fibers, but in that case the required pumping force becomes too large.
【０００４】エルビウムをドープしたファイバの長さ部
分内に光フィルタを挿入することにより増幅器のＡＳＥ
効果を制限することも提案された。この光フィルタは両
方向で雑音のスペクトル成分をブロックする。しかしな
がらこの方法は、増幅器の通過域を制限するという欠点
を有し、増幅器をカスケードに使用する時に危険を伴
う。これらの危険は、周波数がフィルタ毎に少しずつず
れるという事実に起因するものである。The insertion of an optical filter within a length of erbium-doped fiber allows the ASE of the amplifier to be
It was also suggested to limit the effect. This optical filter blocks the spectral components of the noise in both directions. However, this method has the disadvantage of limiting the passband of the amplifier, and involves risks when using the amplifier in a cascade. These dangers are due to the fact that the frequency shifts slightly from filter to filter.
【０００５】これらの問題を解決するために、本発明で
は単式又は複式アイソレータ（ｉｓｏｌａｔｅｕｒ）を
増幅光ファイバの中に挿入して使用することを提案す
る。このようにすると、光ノイズの有害な作用が減少す
るからである。In order to solve these problems, the present invention proposes to use a single or double isolator inserted into an amplification optical fiber. This is because the detrimental effect of the optical noise is reduced.
【０００６】[0006]
【課題を解決するための手段】そこで本発明は、増幅光
ファイバを用いた増幅器であって、ＡＳＥに起因する光
ノイズを減少させる手段を含み、この手段が増幅光ファ
イバの長さ部分の中に挿入されており、この手段がオプ
チカルアイソレータを含んでいることを特徴とする増幅
器を提供する。SUMMARY OF THE INVENTION Accordingly, the present invention is an amplifier using an amplifying optical fiber, which includes means for reducing optical noise due to ASE, wherein the means includes a means for reducing the length of the amplifying optical fiber. , Wherein the means includes an optical isolator.
【０００７】海底伝送システムの場合には、エルビウム
をドープした光ファイバを増幅ファイバとして使用する
と有利である。In submarine transmission systems, it is advantageous to use erbium-doped optical fibers as amplification fibers.
【０００８】[0008]
【実施例】本発明の他の利点及び特徴は、添付図面に基
づく以下の非限定的実施例の説明で明らかにされよう。BRIEF DESCRIPTION OF THE DRAWINGS Other advantages and features of the invention will appear from the following description of non-limiting embodiments, with reference to the accompanying drawings, in which: FIG.
【０００９】驚くべきことに、ＡＳＥの存在によって導
入される利得の制限は本質的に、光ポンピングの方向と
逆の方向に伝搬されるノイズに起因している。本発明で
は、信号と逆の方向に伝搬される光ノイズに起因する飽
和を制限すアイソレータを、ドーピングしたファイバの
中に導入することによって、前述の現象を著しく弱める
ことができる。[0009] Surprisingly, the gain limitation introduced by the presence of the ASE is essentially due to noise propagating in the direction opposite to the direction of optical pumping. In the present invention, the above phenomenon can be significantly reduced by introducing an isolator into the doped fiber that limits saturation due to optical noise propagating in the opposite direction to the signal.
【００１０】図１に示す増幅器１は、増幅すべき光信号
の入力端子２と光信号の出力端子３との間に、波長マル
チプレクサ４と、第１の長さＬのドーピングした光ファ
イバと、アイソレータ５と、第２の長さＬ’のドーピン
グした光ファイバとを順に含んでいる。増幅器を構成す
るこれら種々のエレメントは溶接によって相互に接続さ
れている。マルチプレクサ４は、波長λｓの増幅すべき
光信号Ｓと、波長λｐのポンプ信号Ｐとを結合する。こ
れら２つの信号Ｓ及びＰは増幅光ファイバの入力に導入
される。An amplifier 1 shown in FIG. 1 comprises a wavelength multiplexer 4, an optical fiber doped with a first length L, between an input terminal 2 of an optical signal to be amplified and an output terminal 3 of the optical signal. It includes an isolator 5 and a doped optical fiber of a second length L ′ in order. These various elements that make up the amplifier are interconnected by welding. The multiplexer 4 combines the optical signal S having the wavelength λs to be amplified and the pump signal P having the wavelength λp. These two signals S and P are introduced at the input of the amplification optical fiber.
【００１１】この実施例では、増幅光ファイバが、Ａｌ
2Ｏ3及びＧｅＯ2タイプの酸化物を加えたシリカをベー
スとするコアのガラス質マトリクスを含んでいる。この
ファイバにはエルビウムが１００ｐｐｍの含量でドープ
されている。ファイバのコアとクラッドとの間の屈折率
の差Δｎは３２．１０-3である。In this embodiment, the amplification optical fiber is made of Al
It contains a core vitreous matrix based on silica plus oxides of the type 2 O 3 and GeO 2 . The fiber is doped with erbium at a content of 100 ppm. The refractive index difference Δn between the core and the cladding of the fiber is 32.10 -3 .
【００１２】この増幅器は更に、ポンピング信号発生装
置６も含んでいる。この装置は例えば、波長１．４７５
マイクロメートル、強さ３５ｍＷのポンピング信号を送
出するレーザダイオードを含む。[0012] The amplifier further includes a pumping signal generator 6. This device has, for example, a wavelength of 1.475.
Includes a laser diode that emits a micrometer, 35 mW pumping signal.
【００１３】図２及び図３のグラフは、波長１．５５マ
イクロメートル、強さ−３０ｄＢｍの増幅すべき光信号
について記録されたものである。図２のグラフでは、増
幅ファイバの長さｌ（メートル）の関数として増幅器の
利得Ｇが縦座標にデシベルで示されている。曲線１０
は、アイソレータを具備していない図１の増幅器に関す
る記録に基づいて作成したものである。曲線１１は、ア
イソレータ５を具備した同じ増幅器に関する記録に基づ
いて作成したものである。The graphs of FIGS. 2 and 3 were recorded for an optical signal to be amplified having a wavelength of 1.55 micrometers and an intensity of -30 dBm. In the graph of FIG. 2, the gain G of the amplifier as a function of the length l (meter) of the amplifier fiber is shown in decibels on the ordinate. Curve 10
Was made based on the record for the amplifier of FIG. 1 without an isolator. Curve 11 was made based on a record for the same amplifier with isolator 5.
【００１４】図３のグラフでは、長さｌの関数として増
幅器の雑音指数ＮＦがデシベルで縦座標に示されてい
る。曲線１２は、アイソレータを具備していない増幅器
の記録に基づいて作成したものである。曲線１３は、ア
イソレータ５を具備した同じ増幅器の記録に基づいて作
成したものである。In the graph of FIG. 3, the noise figure NF of the amplifier as a function of the length l is shown in decibels on the ordinate. Curve 12 was created based on the recording of an amplifier without an isolator. Curve 13 was created based on the recording of the same amplifier with isolator 5.
【００１５】オプチカルアイソレータは光源から送出さ
れた信号を伝達せしめ、復路のエネルギを大幅に減少さ
せる。単式アイソレータは、光束を偏光し且つ分割する
立方体と、四分の一波長板とで構成し得る。入射光は前
記立方体によって偏光され、次いで四分の一波長板によ
って円偏光される。復路光束では円偏光の方向が変わ
る。この光束は四分の一波長板を通過することによって
直線的に偏光され、偏光立方体によってブロックされ
る。The optical isolator transmits the signal transmitted from the light source and greatly reduces the energy of the return path. A simplex isolator may consist of a cube that polarizes and splits the light beam and a quarter wave plate. The incident light is polarized by the cube and then circularly polarized by a quarter wave plate. The direction of the circularly polarized light changes in the return light beam. This light beam is linearly polarized by passing through a quarter-wave plate and is blocked by a polarizing cube.
【００１６】オプチカルアイソレータは商品化されてい
る部材である。このアイソレータは該実施例では２つの
波長（増幅すべき信号の波長及びポンピング信号の波
長）に対して透過性を示すものでなければならず、復路
光束の減衰が２５ｄＢより大きくなければならない。必
要であれば複式アイソレータを使用することもできる。The optical isolator is a commercially available member. In this embodiment, the isolator must be transparent to two wavelengths (the wavelength of the signal to be amplified and the wavelength of the pumping signal), and the attenuation of the return beam must be greater than 25 dB. Dual isolators can be used if desired.
【００１７】図２及び図３のグラフから明らかなよう
に、アイソレータを具備していない増幅器では、他の条
件が同じであれば、アイソレータを具備している増幅器
の利得に比肩する利得を得ることはできない。As is clear from the graphs of FIGS. 2 and 3, in the amplifier without the isolator, a gain comparable to the gain of the amplifier with the isolator can be obtained if other conditions are the same. Can not.
【００１８】この条件では、約６０メートルの長さで最
大利得が得られる（図２のグラフ参照）。そこで、アイ
ソレータは、ドーピングしたファイバの先端から２５ｍ
の地点に配置するようにした（Ｌ＝２５ｍ）。これは、
最適長さ６０ｍの約半分に相当する。曲線１１では、ア
イソレータに固有の損失を表す僅かなずれ（ｄｅｃｒｏ
ｃｈｅｍｅｎｔ）が見られる（約１．５ｄＢ）。しかし
ながらこのずれは、５０〜６０ｍの長さのファイバでは
アイソレータを備えた増幅器の利得がアイソレータを備
えていない増幅器の利得より６ｄＢ以上も大きいため、
かなり補償される。Under this condition, the maximum gain is obtained at a length of about 60 meters (see the graph of FIG. 2). Therefore, the isolator is 25 m from the tip of the doped fiber.
(L = 25 m). this is,
This corresponds to about half of the optimum length of 60 m. In curve 11, a slight shift (decro) representing the loss inherent in the isolator
(about 1.5 dB). However, this shift is more than 6 dB greater than the gain of an amplifier without an isolator for a 50-60 m long fiber,
Compensated considerably.
【００１９】図３のグラフが示すように、雑音指数は、
アイソレータを備えた増幅器（曲線１３）ではアイソレ
ータを備えていない増幅器（曲線１２）と比べて１．５
ｄＢ以上改善され得る。この雑音指数の差は、増幅器が
受信時の前置増幅器として機能するか又は複数の増幅器
モジュールを含む装置で線路増幅器として機能し且つこ
の装置に沿ったＡＳＥの蓄積によって生じる問題が臨界
的な場合には、極めて重要であり得る。As shown in the graph of FIG. 3, the noise figure is
The amplifier with isolator (curve 13) is 1.5 times more than the amplifier without isolator (curve 12).
It can be improved by more than dB. This difference in noise figure may be due to the fact that the amplifier functions either as a pre-amplifier during reception or as a line amplifier in a device comprising a plurality of amplifier modules and where the problems caused by the accumulation of ASE along this device are critical. Can be extremely important.
【００２０】本発明の増幅器ではファイバアイソレータ
中に光フィルタを加えることができ、この光フィルタは
必要であればノイズの一部分を同時伝搬でフィルタリン
グする。In the amplifier of the present invention, an optical filter can be added in the fiber isolator, which filters a portion of the noise by co-propagation if necessary.
【図１】本発明の増幅光ファイバを用いた増幅器のブロ
ック図である。FIG. 1 is a block diagram of an amplifier using an amplification optical fiber of the present invention.
【図２】図１の増幅器の利得を増幅光ファイバの長さの
関数として示す比較グラフである。FIG. 2 is a comparative graph showing the gain of the amplifier of FIG. 1 as a function of the length of the amplifying optical fiber.
【図３】同じ増幅器の雑音指数を増幅光ファイバの長さ
の関数として示す比較グラフである。FIG. 3 is a comparative graph showing the noise figure of the same amplifier as a function of the length of the amplified optical fiber.
１ 増幅器 ４ 波長マルチプレクサ Ｌ、Ｌ’ 増幅光ファイバ ６ ポンピング信号発生装置 DESCRIPTION OF SYMBOLS 1 Amplifier 4 Wavelength multiplexer L, L 'Amplification optical fiber 6 Pumping signal generator
フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ Ｈ０４Ｂ 10/16 Ｈ０４Ｂ 9/00 Ｊ 10/17 (56)参考文献 特開 平４−214540（ＪＰ，Ａ) 特開 平４−251828（ＪＰ，Ａ) 特開 平４−250429（ＪＰ，Ａ) 特開 平４−96287（ＪＰ，Ａ) ＩＥＥＥ Ｐｈｏｔｏｎｉｃｓ Ｔｅ ｃｈｎｏｌｏｇｙ Ｌｅｔｔｅｒｓ ｖ ｏｌ．２，ｎｏ．12，866−868（1990) (58)調査した分野(Int.Cl.6，ＤＢ名) H01S 3/10 G02F 1/35 501 H01S 3/07 H01S 3/094 H04B 10/00 ＪＩＣＳＴファイル（ＪＯＩＳ)Continuation of the front page (51) Int.Cl. 6 Identification symbol FI H04B 10/16 H04B 9/00 J 10/17 (56) References JP-A-4-214540 (JP, A) JP-A-4-251828 ( JP, A) JP-A-4-250429 (JP, A) JP-A-4-96287 (JP, A) IEEE Photonics Technology Letters vol. 2, no. 12, 866-868 (1990) (58) Fields investigated (Int. Cl. 6 , DB name) H01S 3/10 G02F 1/35 501 H01S 3/07 H01S 3/094 H04B 10/00 JICST file (JOIS)
Claims (4)
装置と、ポンピング信号を増幅光ファイバを通して送る
光カップリング手段とを有する増幅器であって、ＡＳＥ
に起因する光ノイズを減少させる手段を含んでおり、該
減少させる手段が前記増幅光ファイバの長さ中に挿入さ
れており、前記減少させる手段がオプチカルアイソレー
タを含んでおり、増幅光ファイバ内での該オプチカルア
イソレータの位置は、増幅されるべき光信号とは反対の
方向に伝搬する光ノイズによる利得飽和を該オプチカル
アイソレータが制限するように決められていることを特
徴とする増幅光ファイバを用いた増幅器。1. Amplifying optical fiber and pumping signal generation
Device and pumping signal through amplified optical fiber
An amplifier having optical coupling means, comprising: an ASE
Means for reducing optical noise caused by
A means for reducing is inserted into the length of the amplifying optical fiber, the means for reducing includes an optical isolator, and the optical amplifier in the amplifying optical fiber.
The position of the isolator is opposite to the optical signal to be amplified
Gain saturation due to optical noise propagating in the
An amplifier using an amplifying optical fiber, wherein an isolator is determined to be limited .
ープした光ファイバであることを特徴とする請求項１に
記載の増幅器。2. The amplifier according to claim 1, wherein the amplification optical fiber is an optical fiber doped with erbium.
ルアイソレータを含むことを特徴とする請求項１に記載
の増幅器。3. A means for the reduction, the amplifier according to claim 1, characterized in it to contain Opuchika <br/> Le isolator double.
ファイバの真ん中より手前に挿入されることを特徴とす
る請求項１に記載の増幅器。 4. An optical isolator comprising :
It is inserted before the middle of the fiber.
The amplifier according to claim 1.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR919108226A FR2678740B1 (en) | 1991-07-02 | 1991-07-02 | AMPLIFIER WITH OPTICAL FIBER AMPLIFIER. |
| FR9108226 | 1991-07-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05211367A JPH05211367A (en) | 1993-08-20 |
| JP2852161B2 true JP2852161B2 (en) | 1999-01-27 |
Family
ID=9414589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4174415A Expired - Fee Related JP2852161B2 (en) | 1991-07-02 | 1992-07-01 | Amplifier using amplified optical fiber |
Country Status (22)
| Country | Link |
|---|---|
| US (1) | US5295217A (en) |
| EP (1) | EP0521763B1 (en) |
| JP (1) | JP2852161B2 (en) |
| KR (1) | KR930003524A (en) |
| CN (1) | CN1039942C (en) |
| AT (1) | ATE151206T1 (en) |
| AU (1) | AU656779B2 (en) |
| CA (1) | CA2072789A1 (en) |
| DE (1) | DE69218679T2 (en) |
| DK (1) | DK0521763T3 (en) |
| ES (1) | ES2099230T3 (en) |
| FI (1) | FI923014A (en) |
| FR (1) | FR2678740B1 (en) |
| HK (1) | HK1007639A1 (en) |
| IL (1) | IL102312A (en) |
| MX (1) | MX9203865A (en) |
| MY (1) | MY109638A (en) |
| NO (1) | NO922563L (en) |
| NZ (1) | NZ243246A (en) |
| SG (1) | SG44757A1 (en) |
| TW (1) | TW200609B (en) |
| ZA (1) | ZA924886B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2264807B (en) * | 1992-02-20 | 1995-10-04 | Univ Southampton | Optical amplifier |
| JP2871370B2 (en) * | 1993-01-20 | 1999-03-17 | キヤノン株式会社 | Output control method and device |
| FR2708354B1 (en) * | 1993-07-26 | 1995-09-01 | France Telecom | Optical fiber optic amplifier in doped fluorinated glass and method of manufacturing this amplifier. |
| JPH08204647A (en) * | 1994-11-25 | 1996-08-09 | Sumitomo Electric Ind Ltd | Optical relay transmitter and optical communication method |
| FR2715481B1 (en) * | 1994-01-26 | 1996-02-16 | Mathilde Semenkoff | Optical fiber optic amplifier in doped fluorinated glass and method of manufacturing this amplifier. |
| KR19980046369A (en) * | 1996-12-12 | 1998-09-15 | 안정오 | Human body amplifier |
| KR100280968B1 (en) | 1997-12-10 | 2001-02-01 | 윤종용 | Optical fiber amplifier using a synchronized etal on filter |
| IT1313112B1 (en) * | 1998-08-25 | 2002-06-17 | Samsung Electronics Co Ltd | LONG BAND OPTICAL FIBER AMPLIFIER WITH REINFORCED POWER CONVERSION EFFICIENCY |
| US6546168B1 (en) | 1999-12-10 | 2003-04-08 | Finisar Corporation | Integrated isolator fused coupler method and apparatus |
| US6381063B1 (en) * | 2000-03-16 | 2002-04-30 | Corning Incorporated | Long band optical amplifier |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01246045A (en) * | 1988-03-28 | 1989-10-02 | Yamazaki Mazak Corp | Setting control of machining coordinate system in machine tool |
| JP2546711B2 (en) * | 1988-12-22 | 1996-10-23 | 国際電信電話株式会社 | Er-doped optical fiber laser device |
| US5058974A (en) * | 1989-10-06 | 1991-10-22 | At&T Bell Laboratories | Distributed amplification for lightwave transmission system |
| US5039199A (en) * | 1989-12-29 | 1991-08-13 | At&T Bell Laboratories | Lightwave transmission system having remotely pumped quasi-distributed amplifying fibers |
| JP2843129B2 (en) * | 1990-08-06 | 1999-01-06 | 日本電信電話株式会社 | Multi-stage optical amplifier |
| JPH04214540A (en) * | 1990-12-12 | 1992-08-05 | Fujitsu Ltd | Optical amplifier |
| JP2734209B2 (en) * | 1991-01-28 | 1998-03-30 | 日本電気株式会社 | Optical fiber amplifier |
| JP3129455B2 (en) * | 1991-01-29 | 2001-01-29 | 富士通株式会社 | Optical amplifier |
| US5140456A (en) * | 1991-04-08 | 1992-08-18 | General Instrument Corporation | Low noise high power optical fiber amplifier |
| US5191586A (en) * | 1991-07-18 | 1993-03-02 | General Instrument Corporation | Narrow band incoherent optical carrier generator |
| US5177634A (en) * | 1991-10-25 | 1993-01-05 | Bell Communications Research, Inc. | High gain limiting erbium-doped fiber amplifier with wide dynamic range |
| US5185826A (en) * | 1992-02-07 | 1993-02-09 | At&T Bell Laboratories | Hybrid pumping arrangement for doped fiber amplifiers |
-
1991
- 1991-07-02 FR FR919108226A patent/FR2678740B1/en not_active Expired - Fee Related
-
1992
- 1992-06-22 NZ NZ243246A patent/NZ243246A/en unknown
- 1992-06-25 IL IL10231292A patent/IL102312A/en not_active IP Right Cessation
- 1992-06-26 AU AU18622/92A patent/AU656779B2/en not_active Ceased
- 1992-06-29 EP EP92401837A patent/EP0521763B1/en not_active Expired - Lifetime
- 1992-06-29 NO NO92922563A patent/NO922563L/en unknown
- 1992-06-29 DE DE69218679T patent/DE69218679T2/en not_active Expired - Fee Related
- 1992-06-29 SG SG1996007094A patent/SG44757A1/en unknown
- 1992-06-29 DK DK92401837.7T patent/DK0521763T3/da active
- 1992-06-29 FI FI923014A patent/FI923014A/en unknown
- 1992-06-29 ES ES92401837T patent/ES2099230T3/en not_active Expired - Lifetime
- 1992-06-29 AT AT92401837T patent/ATE151206T1/en not_active IP Right Cessation
- 1992-06-30 CA CA002072789A patent/CA2072789A1/en not_active Abandoned
- 1992-06-30 MY MYPI92001090A patent/MY109638A/en unknown
- 1992-07-01 KR KR1019920011670A patent/KR930003524A/en not_active Application Discontinuation
- 1992-07-01 US US07/907,716 patent/US5295217A/en not_active Expired - Lifetime
- 1992-07-01 ZA ZA924886A patent/ZA924886B/en unknown
- 1992-07-01 JP JP4174415A patent/JP2852161B2/en not_active Expired - Fee Related
- 1992-07-01 MX MX9203865A patent/MX9203865A/en not_active IP Right Cessation
- 1992-07-02 CN CN92105304A patent/CN1039942C/en not_active Expired - Fee Related
- 1992-07-28 TW TW081105957A patent/TW200609B/zh active
-
1998
- 1998-06-25 HK HK98106822A patent/HK1007639A1/en not_active IP Right Cessation
Non-Patent Citations (1)
| Title |
|---|
| ＩＥＥＥ Ｐｈｏｔｏｎｉｃｓ Ｔｅｃｈｎｏｌｏｇｙ Ｌｅｔｔｅｒｓ ｖｏｌ．２，ｎｏ．１２，８６６−８６８（１９９０） |
Also Published As
| Publication number | Publication date |
|---|---|
| SG44757A1 (en) | 1997-12-19 |
| FI923014A (en) | 1993-01-03 |
| US5295217A (en) | 1994-03-15 |
| NO922563L (en) | 1993-01-04 |
| MX9203865A (en) | 1993-07-01 |
| JPH05211367A (en) | 1993-08-20 |
| ZA924886B (en) | 1993-03-31 |
| NO922563D0 (en) | 1992-06-29 |
| EP0521763A1 (en) | 1993-01-07 |
| MY109638A (en) | 1997-03-31 |
| AU1862292A (en) | 1993-01-07 |
| TW200609B (en) | 1993-02-21 |
| EP0521763B1 (en) | 1997-04-02 |
| ATE151206T1 (en) | 1997-04-15 |
| CN1069130A (en) | 1993-02-17 |
| FR2678740B1 (en) | 1994-06-10 |
| ES2099230T3 (en) | 1997-05-16 |
| CN1039942C (en) | 1998-09-23 |
| CA2072789A1 (en) | 1993-01-03 |
| FI923014A0 (en) | 1992-06-29 |
| NZ243246A (en) | 1995-03-28 |
| IL102312A (en) | 1995-11-27 |
| FR2678740A1 (en) | 1993-01-08 |
| DE69218679T2 (en) | 1997-07-10 |
| AU656779B2 (en) | 1995-02-16 |
| HK1007639A1 (en) | 1999-04-16 |
| KR930003524A (en) | 1993-02-24 |
| DK0521763T3 (en) | 1997-04-21 |
| DE69218679D1 (en) | 1997-05-07 |
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